9Andrey Arshavin - £16.95m

A complicated deal which was finally officially announced some 24 hours after the winter transfer window of January 2009 had closed.

The Russia international arrived amid a snowstorm and although he produced flurries of magic - including a four-goal showing against Liverpool in April 2009 - he never really hit the heights which had made him such a sought-after asset at Zenit.

8Lucas Perez - £17.1m

A 17-goal season at Deportivo La Coruna convinced Arsenal to make their move in the summer of 2016, but the Spaniard struggled for game time up against Alexis Sanchez and Olivier Giroud, and managed just seven goals in 21 appearances.

Looked bright when offered an opportunity to impress, but grew frustrated at a lack of minutes and is now on loan at Deportivo La Coruna.

7Jose Antonio Reyes - £17.4m

The most expensive signing in Arsenal’s history until a recent loosening of the purse strings at Emirates Stadium.

The Spaniard joined from Sevilla in January 2004 and helped the ‘Invincibles’ to the Premier League title before going on to taste FA Cup glory the following season and gracing the Champions League final in 2006.

6Granit Xhaka - £34m

With the Gunners having struggled down the years to replace some iconic figures in the box-to-box midfield department, big money was spent to land the Switzerland international from Borussia Monchengladbach.

Disciplinary problems continued to haunt him early on during his debut season in England, but he eventually won the FA Cup, perhaps repaying part of Arsenal's investment.